/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package core.net;

import java.io.IOException;
import java.net.InetAddress;
import java.net.InetSocketAddress;
import java.net.Socket;
import java.net.UnknownHostException;
import java.nio.channels.SocketChannel;

import javax.net.SocketFactory;

/**
 * Specialized SocketFactory to create sockets with a SOCKS proxy
 */
public class StandardSocketFactory extends SocketFactory {

	/**
	 * Default empty constructor (for use with the reflection API).
	 */
	public StandardSocketFactory() {
	}

	/* @inheritDoc */
	@Override
	public Socket createSocket() throws IOException {
		/*
		 * NOTE: This returns an NIO socket so that it has an associated
		 * SocketChannel. As of now, this unfortunately makes streams returned
		 * by Socket.getInputStream() and Socket.getOutputStream() unusable
		 * (because a blocking read on input stream blocks write on output
		 * stream and vice versa).
		 * 
		 * So users of these socket factories should use
		 * NetUtils.getInputStream(socket) and NetUtils.getOutputStream(socket)
		 * instead.
		 * 
		 * A solution for hiding from this from user is to write a
		 * 'FilterSocket' on the lines of FilterInputStream and extend it by
		 * overriding getInputStream() and getOutputStream().
		 */
		return SocketChannel.open().socket();
	}

	/* @inheritDoc */
	@Override
	public Socket createSocket(InetAddress addr, int port) throws IOException {

		Socket socket = createSocket();
		socket.connect(new InetSocketAddress(addr, port));
		return socket;
	}

	/* @inheritDoc */
	@Override
	public Socket createSocket(InetAddress addr, int port,
			InetAddress localHostAddr, int localPort) throws IOException {

		Socket socket = createSocket();
		socket.bind(new InetSocketAddress(localHostAddr, localPort));
		socket.connect(new InetSocketAddress(addr, port));
		return socket;
	}

	/* @inheritDoc */
	@Override
	public Socket createSocket(String host, int port) throws IOException,
			UnknownHostException {

		Socket socket = createSocket();
		socket.connect(new InetSocketAddress(host, port));
		return socket;
	}

	/* @inheritDoc */
	@Override
	public Socket createSocket(String host, int port,
			InetAddress localHostAddr, int localPort) throws IOException,
			UnknownHostException {

		Socket socket = createSocket();
		socket.bind(new InetSocketAddress(localHostAddr, localPort));
		socket.connect(new InetSocketAddress(host, port));
		return socket;
	}

	/* @inheritDoc */
	@Override
	public boolean equals(Object obj) {
		if (this == obj)
			return true;
		if (obj == null)
			return false;
		if (!(obj instanceof StandardSocketFactory))
			return false;
		return true;
	}

	/* @inheritDoc */
	@Override
	public int hashCode() {
		// Dummy hash code (to make find bugs happy)
		return 47;
	}

}
